In an analysis of organic chemical substances, particularly agricultural chemicals, an analysis method by a liquid chromatography has been employed (for example, see Patent reference 1). Additionally, for an analysis of agricultural chemicals used in golf courses, a liquid chromatography has been also utilized (for example, see Patent reference 2). After that, a safety problem on residual agricultural chemicals adhered to farm products arose, which resulted in utilizing not only a liquid chromatography but also a gas chromatography. Further, methods have been proposed that a gas chromatography is combined with infrared absorption spectrum, and a micro-trap is used as a pretreatment of a gas chromatography (for example, see Patent references 3 and 4). At the same time, as an environment problem becomes acknowledged, an analysis method of dioxin has been also studied (for example, see Patent reference 5).    Patent reference 1 Japanese Unexamined Patent Publication Hei 6-331618 (331618/1994)    Patent reference 2 Japanese Unexamined Patent Publication Hei 5-306998 (306998/1993)    Patent reference 3 Japanese Unexamined Patent Publication Hei 8-170941 (17094/1996)    Patent reference 4 Japanese Unexamined Patent Publication 2002-328121    Patent reference 5 Japanese Unexamined Patent Publication 2002-48688